Former US Secretaries of Defense Robert Gates (l.) and Leon Panetta, discuss their thoughts on Syria and other current affairs with CNN political analyst David Gergen (r.) at a forum at Southern Methodist University in Dallas on Tuesday, Sept. 17, 2013. Gates and Panetta expressed their concerns about President Obama's decision last month to ask Congress for its support for military action against the Syrian regime.

“When the president of the United States draws a red line, the credibility of this country is dependent on him backing up his word,” Panetta said during a panel discussion at Southern Methodist University.

He said Obama should not “subcontract” his decision to lawmakers. "Mr. President, this Congress has a hard time agreeing as to what the time of day is," he added.

Meanwhile, Gates said action “would be throwing gasoline on a very complex fire in the Middle East.”

“Haven’t Iraq, Afghanistan, and Libya taught us something about the unintended consequences of military action once it’s launched?” he said.

Gates also suggested that a diplomatic solution that would allow Russia to oversee and guarantee the destruction of Syria’s chemical weapons reserves is folly and that Russian President Vladimir Putin isn’t trustworthy. Obama has backed off his initial call for military action, which was received poorly in Congress and among the general public, in the hope that such a compromise could work.

Gates, who was appointed by President George W. Bush and was the only holdover from that administration to serve Obama, also said that a congressional vote against the president’s push for intervention “would weaken him.”

“It would weaken our country,” he said. “It would weaken us in the eyes of our allies, as well as our adversaries around the world.”

Instead, Gates said he would impose sanctions that marked members of the Assad government as war criminals and would increase support for credible allies within the Syrian resistance, according to The New York Times.

Now enjoying private life, both men are writing books about their time in Washington, and those who embark on memoirs often seek to make news to spark interest. But Gates and Panetta, a Democrat, are widely viewed within the political and intelligence worlds as practical, thoughtful, and experienced policy gurus. Neither is a showboater.

So these latest words from Gates and Panetta are particularly stinging, even though much of official Washington has weighed in with varying degrees of concern about how Obama has handled the Syria matter in the wake of a chemical weapons attack.

The headlines have played accordingly:

“Gates and Panetta Take Obama to Task,” Commentary magazine suggests.

“It is rare enough for current or former White House aides to publicly criticize a president still in office, as David Stockman and George Stephanopoulos notoriously did in the 1980s and 1990s respectively,” the magazine wrote. “It is virtually unheard of for senior cabinet members to do so. Which ... makes it all the more shocking and telling that two of President Obama’s former secretaries of defense – both models of discretion – have gone public with criticism of his handling of Syria.”

Another aspect of the pair’s remarks that worries the Commentary writer and others: They see in Obama’s approach to Syria a “dangerous signal” being sent to Iran.

“Iran is paying very close attention to what we’re doing,” Panetta said, per The New York Times. “There’s no question in my mind they’re looking at the situation, and what they are seeing right now is an element of weakness.”

Obama’s current Defense secretary, Chuck Hagel, shrugged off the episode while declaring his “greatest respect” for his predecessors.